Sitara as a Smart Servo: Industrial Communications

Standard Ethernet alone does not have deterministic capabilities. You need a protocol running over Ethernet to get the level of performance required by today's factories. Unfortunately, there isn't a one-size-fits-all solution for deterministic Ethernet. The industrial Ethernet market is very fragmented between different Ethernet protocols like Ethernet/IP, PROFINET, EtherCAT, OPC UA, CC-Link IE, Sercos III, MECHATROLINK III, and the list goes on.
Fortunately for the servo drive market, though, there's really just three main protocols used around the world, and they're EtherCAT, PROFINET IRT, and Ethernet IP. In fact, these three make up roughly 63% of the industrial Ethernet market, according to HMS's 2017 market report.
For servo drives, EtherCAT seems to be the favorite because of its low-cost model and low-latency performance. In fact, TI Sitara processors can achieve EtherCAT cycle times of as low as 31.25 microseconds. The high performance and low cost is especially appealing to the Chinese market where many of the world's factories are located.
PROFINET IRT comes in second in terms of popularity among server drive manufacturers, and Ethernet IP comes in third. Both of these protocols have a strong base in their home regions, thanks to the industry titans backing them, and they're now starting to get attention in other regions.
Other protocols gaining traction in the industry are SERCOS and the MECHATROLINK. SERCOS offers a performance level similar to EtherCAT, but there's not near as many ecosystem partners, so finding a system solution for SERCOS is a little tougher. MECHATROLINK was initially developed by Escala. But this standard has been kept close for many years. Recently, Escala opened the standard up, and actually allowed TI Sitara processors to be one of the first devices other than their ASIQ to support MECHATROLINK III. Now that the standard is open, there's been interest from other manufacturers to make use of this high-performance protocol.
In order to mitigate some of this risk, designers are adopting CPUs with the ability to support various protocols, and TI Sitara processors can support every protocol mentioned on this page. These are not the only 5 protocols available to server drives, but they are some of the more popular ones for this industry. The decision on which protocol to support can be daunting, since by choosing one standard, you effectively limit yourself to that one piece of the market. To mitigate some of this risk, designers are adopting CPUs with the ability to support various protocols, and TI Sitara processors can support every protocol mentioned on this page.
An alternative solution to the fragmented industrial Ethernet market is time-sensitive networking, or TSN. This group of standards is still in definition phase, though, so it's still to be determined just how this will play out. It's expected that many of the industrial Ethernet standards will adopt TSN as a component of the protocol, so that could be a potential trend to look out for in the near future. 单独的标准以太网没有 确定性功能。 你需要一个通过以太网运行的协议 来获得当今工厂所需的性能水平。 不幸的是，对于确定性以太网而言， 没有一种通用的解决方案。 工业以太网市场 有各种不同的以太网协议，他们之间非常分散， 如Ethernet/ IP，PROFINET，EtherCAT，OPC UA，CC-Link IE， Sercos III，MECHATROLINK III等等。 幸运的是，对于伺服驱动器市场而言， 世界上只有三种主要协议， 它们是EtherCAT，PROFINET IRT 和Ethernet IP。 事实上，根据HMS 2017年的市场报告， 这三者占工业以太网市场的 63％左右。
对于伺服驱动器，EtherCAT 似乎是最受欢迎的，因为它具有低成本模型和低延迟 性能。 实际上，TI Sitara处理器可以 实现低至31.25微秒的EtherCAT周期时间。 高性能和低成本 对于世界上许多工厂所在的中国市场 尤其具有吸引力。
PROFINET IRT在服务器驱动器制造商中的 受欢迎程度排在第二位， Ethernet IP排在第三位。 这两个协议都在其所在地区拥有 强大的基础，这得益于支持它们的行业巨头， 它们现在开始受到其他地区的关注。
其他获得业界关注的协议是 SERCOS和MECHATROLINK。 SERCOS提供与EtherCAT类似的性能水平， 但没有那么多的生态系统合作伙伴， 因此为SERCOS寻找系统解决方案有点困难。 MECHATROLINK最初由Escala开发。 但是这个标准已经保持了很多年。 最近，Escala开启了标准， 并且实际上允许TI Sitara处理器 成为除ASIQ以外的首批支持 MECHATROLINK III的设备之一。 现在该标准已经开放， 其他制造商 一直有兴趣使用这种高性能协议。
为了减轻这种风险， 设计人员采用的CPU能够 支持各种协议，TI Sitara处理器 可以支持本页提到的每个协议。 这些并不是服务器驱动器 可用的唯一5种协议， 但它们是这个行业中一些比较流行的协议。 决定支持哪种协议可能是个 艰巨的任务，因为选择一个标准， 你实际上将自己限制在 市场的一个部分。 为了降低这种风险，设计人员 采用的CPU能够 支持各种协议，TI Sitara处理器 可以支持本页提到的每个协议。 分散的工业以太网市场的替代解决方案 是时间敏感的网络，又称TSN。 然而，这组标准仍然处于定义阶段， 因此仍然需要确定它 将如何发挥作用。 预计许多工业以太网标准 将采用TSN作为协议的一个组成部分， 因此这可能在不久的将来 成为潜在的趋势。

Description

March 29, 2019

Standard Ethernet alone does not have the ability to be deterministic. You need a protocol running over Ethernet to get the level of performance required by today’s factories. Unfortunately, there isn’t a one-size-fits-all solution for deterministic Ethernet in the factory. The industrial Ethernet market is very fragmented between different Ethernet protocols like EtherNet/IP®, PROFINET, EtherCAT, OPC UA, CC-Link IE, SERCOS III, Mechatrolink III ... and the list goes on. Fortunately for the servo drive market, there are really just three main protocols used around the world: EtherCAT, Profinet, and EtherNet/IP. In fact, these three protocols make up roughly 63 percent of the industrial Ethernet market.